Kowal's ruling, first reported by The Arizona Daily Star, said the district's Mexican-American Studies program violated state law by having one or more classes designed primarily for one ethnic group, promoting racial resentment and advocating ethnic solidarity instead of treating students as individuals.

Teaching oppression objectively is quite different than actively presenting material in a biased, political and emotionally charged manner, which is what occurred in (Mexican-American Studies) classes.

- Judge Lewis Kowal

The judge, who found grounds to withhold 10 percent of the district's monthly state aid until it comes into compliance, said the law permits the objective instruction about the oppression of people that may result in racial resentment or ethnic solidarity.

"However, teaching oppression objectively is quite different than actively presenting material in a biased, political and emotionally charged manner, which is what occurred in (Mexican-American Studies) classes," Kowal wrote.

Huppenthal has 30 days to accept, reject or modify the ruling. If he accepts the judge's decision, the district has about 30 days to appeal the ruling in Superior Court.

"In the end, I made a decision based on the totality of the information and facts gathered during my investigation — a decision that I felt was best for all students in the Tucson Unified School District." Huppenthal said in a written statement.

Messages left for a district spokeswoman Tuesday night weren't immediately returned. In the past, district officials have said they can't afford to the financial hit that Huppenthal's decision would bring.

The battle over the ethnic studies program escalated shortly after Arizona's heavily scrutinized immigration enforcement law was passed in April 2010.

Huppenthal ordered a review of the program when he took office in January after his predecessor, Tom Horne, said the Mexican-American Studies program violated state law and that Huppenthal would have to decide whether to withhold funding.

Huppenthal, a Republican, had voted in favor of the ethnic studies law as a state senator before becoming the state's schools chief.